Exploring, drilling, completing, and operating hydrocarbon and other wells are generally complicated, time consuming and ultimately very expensive endeavors. In recognition of these expenses, added emphasis has been placed on well access, monitoring and management throughout the productive life of the well. That is to say, from a cost standpoint, an increased focus on ready access to well information and/or more efficient interventions have played key roles in maximizing overall returns from the completed well.
By the same token, added emphasis on completions efficiencies may also play a critical role in maximizing returns. That is, enhancing efficiencies over the course of well testing, hardware installation and other standard up front tasks may also ultimately improve overall returns on the significant investments placed in well completions. For example, a host of well testing applications may be run upon completion of initial drilling operations but in advance of casing and other hardware installations. Such tests may be carried out by a testing tool outfitted with a ball valve, a circulation valve, and other features directed at acquiring flow, pressure, and other downhole data.
The described ‘dual valve’ testing tool may be utilized in conjunction with temporary packer-based drill stem isolation. Thus, the tool may be delivered to a known downhole location, acquire relevant sampling information, and be moved to another location for repeating of the data acquisition process.
Given ever increasing well depths and other factors, the dual valve testing tool may be configured to operate as described without the use of heavy cabling. For example, valve actuation may be triggered by way of pressure pulse signaling from surface. Thus, the dual valve tool is often referred to as an ‘intelligent remote’ dual valve tool or “IRDV tool” with different pressure pulse signatures from surface signaling different valve opening and closing actuations.
Once more, power requirements for valve shifting and other actuations may be met by taking advantage of the natural differential pressure that exists between the downhole environment and the atmospheric pressure provided to the tool from the oilfield surface. In fact, even powering requirements for solenoid triggering of such actuations may be met by use of small scale piezo-material. As such, the overall IRDV tool footprint and testing deployment weight may be kept to a minimum.
Unfortunately, given the ever increasing well depths and the incomplete, largely uncontrolled, nature of the well at this stage of completions, the testing environment may be particularly challenging in terms of the high temperatures and differential pressures involved. For example, the hydraulic nature of the tool may result in hydrostatic pressure hydraulics (i.e. in communication with the downhole environment) that may be in excess of 30,000 PSI above the atmospheric pressure hydraulics (i.e. determined at the oilfield surface).
While the described differential certainly provides more than enough potential power for driving the noted actuations, the differential may be more than the hydraulics of the tool are able to maintain throughout testing operations. For example, the architectural layout of tool components may lead to thinner walled or less structurally sound regions of atmospheric pressure hydraulics. These locations may be susceptible to failure when faced with holding back such dramatically high pressures. Further, the failure rate may be exacerbated where similarly dramatic high temperatures are found downhole.
Ultimately, due to tool failure rates of IRDV tools in such high pressure incomplete wells, operators may elect to employ alternate, more cumbersome, modes of power and actuation. However, as a practical matter, IRDV tools as described are generally employed with failure resulting in significant cost and time delays associated with re-outfitting, positioning, and testing of various well locations.